Reflector focusing apparatus



May 23, 1933. H. J. GRAHAM REFLECTOR FOCUSING APPARATUS Filed May 16. 1929 3 Sheets-Sheet 1 IN VEN TOR.

BY HERBERT J. GRAHAM A TTORNEY.

May 23, 1933. H. J. GRAHAM REFLECTOR FOCUSING APPARATUS Filed May 16, 1929 3 Sheets-Sheet 2 26 s. INVENTOR HERBERT J. GRAHAM A TTORNE Y.

May 23, 1933. H. J. GRAHAM REFLECTOR FOCUSING APPARATUS Filed May 16, 1929 3 Sheets-Sheet 5 INVENTOR.

HERBERT d. GRAHAM A TTORNE Y.

Patented May 23, 1933 UNITED STATES PATENT OFFICE HERBERT J. GRAHAM, OI PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO ELECTRIC SERVICE SUPPLIES COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORA- TION OF PENNSYLVANIA REFLECTOR FOCUSING APPARATUS Application filed May 16,

This invention relates to lamp focusing apparatus and more particularly to an apparatus for and method of determining the true optical axis of a reflector as distinguished from its geometrical axis, the apparatus being further adapted to accurately position upon the reflector a lamp socket the axis of which is in coincidence with the predetermined optical axis of the reflector.

Heretofore and prior to this invention it has beenan exceedingly difiicult, if not impossible task to accurately determine the proper focal position of a light source with respect to its reflector in order to obtain a maximum of reflected light in a given direction. A usual expedient in lamps embodying a parabolic or generally dish-shaped reflector for the light source is to mount the lamp socket upon the base of the reflector in such manner that the electric bulb projects along the geometrical axis thereof, the lamp socket and its associated bulb being normally adjustable axially of the reflector. So long as this geometrical axis is coincident with the true optical axis of the reflector a satisfactory relation is had between the light source and the reflector. In practice, however, it has been found that is the ordinary run of reflectors as used commercially, the geometrical axis is not ordinarily coincident with the true optical axis of the reflector with the result that an unsatisfactory condition arises when the light source is positioned at some point along the geometrical axis of the reflector.

It will be understood, of course, that in a reflector which is theoretically correct in design and construction the geometrical and optical axes thereof are coincident. Due, however. to faulty design and irregularities in the shape of the reflector and to imperfections in the reflecting surface thereof, the true optical axis is shifted out of coincidence with the geometrical axis and it is an object of the present invention to determine the point where this true optical axis passes through the reflector. Obviously, the theoretical light center of the reflector is at some point along this true optical axis.

By actual tests in the field or in the lab- 1929. Serial No. 363,461.

oratory it is, of course, possible to determine the operating efliciency of a reflect-or, but only after the reflector has been installed within its supporting housing. In the event that these tests showed the reflector as having an operating efficiency below that which is deemed desirable, the lamp as a whole would have to be discarded or the reflector removed therefrom and a new one inserted in its place. Obviously, this is an expensive procedure and often results in discarding an entire lighting unit when only the reflector is defective. It is accordingly a further object of this invention to provide an appa ratus for and method of determining, in advance of its actual installation within a lamp body, the reflecting efliciency of a reflector.

A still further object of the invention the provision of an apparatus for determining, in an expeditious manner and witha high degree of exactitude. when a reflector is so defective that it is unsuitable for use in a lighting unit, wherein it is important to obtain a maximum of uniformly distributed reflected rays of light for projection over comparatively great distances or areas, examples of such units being automotive vehicle and locomotive head-lights, search lights, flood-lights, and the like.

Having located the optical axis of a given reflector and having determined that the reflecting efliciency thereof is above a predetermined minimum value, it is a still further object of the present invention to provide means forming part of the apparatus for securing upon the reflector a lamp socket sup porting ferrule or sleeve the axis of which is coincident with the predeterminedly located optical axis of the reflector.

A still further object of the invention is the provision of a. lamp focusing apparatus which is operative to automatically insure the positionment of a lamp socket upon a parabolic reflector with the axis of the socket extending in a direction normal to the plane k of the marginal edge or rim of the reflector.

Other objects of the invention and advantages resulting therefrom will appear more fully hereinafter.

The invention consists substantially in the combination, construction, location and relative arrangement and operation of parts, all as will be described more fully hereinafter, as shown in the accompanying drawings and as finally pointed out in the appended claims. In the said accompanying drawings, which for purposes of illustration show a preferred construction of the invention:

Figure 1 is a top plan view of an apparatus constructed in accordance with the present invention;

Figure 2 is a vertical sectional view of the apparatus taken on the line 22 of Figure 1;

Figure 3 is a horizontal view taken on the line 3-3 of Figure 1;

Figure 4 is a side elevational view of that portion of the apparatus which is shown in Figure 3;

Figures 5 and 6 are plan views of the upper light intercepting member, Figure 5 showing the relative position of light rays as reflected from a perfect reflector while Figure 6 shows the relative position of light rays as reflected from an imperfect reflector;

Figure 7 is an enlarged cross-sectional view of the upper and lower punch elements of the apparatus, the said elements being shown in separated relation with a centrally apertured reflector positioned therebetween, the reflector being provided with a flanged ferrule and the lower punch element with a coacting flanged ferrule;

Figure 8 is a similar view of the punch elements, the upper element thereof being shown in lowered position with respect to the reflector ferrule but still not engaging the lower punch element; 7

Figure 9 shows the upper punch element in still further lowered position with the lower end of the reflector ferrule just engaging the ferrule carried by the lower punch element, the reflector being shown shifted radially with respect to the upper punch element and its surrounding ferrule; and

Figure 10 shows the upper and lower punch elements in ultimate clamping position whereby to force the ferrules into telescoping relation with the flanges thereof embracing opposite surfaces of the reflector. the said ferrules constituting a lamp socket receiving sleeve which is coaxial with the predeterininedly located optical axis of the reflector.

Referring now to the drawings and more particularly to Figure 2 thereof it will be observed that the apparatus of the present invention comprises a lower base plate 10 and an upper ring member 11, the said base plate and ring member being maintained in vertically spaced relation by a plurality of parallel, vertically extending rods 12. Preterably. the upper and lower ends of each rod 12 is reduced in diameter. as at 13, the reduced portions being projected through suitable circumferentially spaced openings 14 provided in the base plate 10 and the upper member 11. Nuts 15, which threadedly engage the oppositely projecting extremities of the rods 12, elfectually preclude vertical displacement between the lower base plate 10 and the upper ring member 11.

The lower base plate 10 constitutes the foundation member of the apparatus and to this end the said plate is preferably provided with a plurality of supporting feet 16 each of which is apert-ured, as at 17, for insertion therethrough of a securing element (not shown). The upper ring member 11 is providcd with a plurality of radially extending arms 18, preferably not more than three, the inner ends of which support a central hub 19, the axis of which is coincident with the vertical center line of the apparatus. Extending transversely across the top of the upper member 11 is a shaft 20, said shaft being suitably journalled in a plurality of horizontally aligned upstanding bosses 21, 22 and 23, the bosses 21 and 22 being formed upon opposite sides of member 11 and the boss 23 upon the central hub 19. As appears most clearly in Figure 1 the bosses 21, 22 and 23 are so arranged that the shaft 20, which is journalled therein, is rotatable about an axis disposed to one side of the central hub 19. Suitably keyed to the shaft 20 and arranged for rotation in a vertical plane intersecting the vertical axis of the apparatus is a pinion gear 24.

The lower plate member 10 is centrally apertured, as at 25, and secured thereto, preterably by the bolts 26, is an upwardly extending sleeve 27, the vertical bore 28 of which is in alignment with the central aperture 25 of the bottom plate member. The upper end of the bore 28 of sleeve 27 is enlarged, as at 29. to provide a seat for a female die 30. the latter being keyed, as at 31, to effectually prevent relative rotation thereof with respect to its seat.

Slidably received within the central hub 19 of the upper member 11 is a vertically extending member 32, one side of which is flattened, as at 33 (see Figure 1), and longitudinally grooved, as at 34, for reception of a rack element This rack 35, which is secured in position by the screws 36. is adapted for meshing engagement with the pinion gear 24 carried upon the transverse shaft 20. \Vhile the rack 35 is herein described as being in the form of a removable element, it will h understood that it may be formed as an integral part of the vertically extending member 32. The lower end of the member 32 is recessed, as at 37, and provided upon its external surface with an annular flange 38.

Depending from said lower end of the member 32 is a substantially cup-shaped member 39. the upper edge of which is provided with an annular flange 40 adapted to be secured to the flange 38 by means of the screws 41. The closed bottom 42 of the member 39 is provided with downwardly projecting stem 43 constituting the upper male die of the apparatus. rom the foregoing it will be apparent that upon rotation of the transverse shaft 620 and the consequent rotation of the pinion 24 which is in engagement with the rack 35, the latter will be caused to move downwardly and so force the upper male die 43 into operatiug engagement with the lower female die 30 carried by the base plate of the apparatus. Preterably, .the upper edge of the female die concaved, as fat 44, to provide a seat for the convexed bottom wall 42 of the male die member 39.

Disposed within the central recess of member 39 is a trausversely arranged plate ll-5, set screws 46, projecting through the side walls ,of member 39, being employed to secure said plate in fixed position. Carried by the fiigcd plate 45 is a second plat 47, this scCQnd plate being adjustable toward and away from the fixed plate by means of the adju'stin screws 48. The superposed plates 45 and are complementally apertured to provide a spherically shaped seat for a lamp soclgret supporting member of substantially spherical shape. This member 50 is centrally apertured to receive a socket 51 for a light source in the form of an electric bulb 52 having a concentrated filament. It will be apparent that the arrangement just described permits the bulb 52 to be universally adjusted within the seat formed between the plate members 45 and {1-7, while the set screws 46 permit a limited axial adjustment of said plate members, as a unit, within the member 35), Provided in the annular wall of the member 38 are a plurality of circumferentially spaced groups of vertically spaced transverse apertures ,53, the axes of which converge in a single point located centrally within the central recess of member 3 9, Pref; erably, four groups of these vertically spaced apertures are provided in the wall of memher- 3 9, the groups being s aced ninety degrees apart lYith the lamp ulb 52 positionally adiusted o t a its nc nt te fi am is coippident the point at which the axes of apertures converge, and in view of the fact that these apertures are of very small clianieters compared to their len ths, there will be produced a series of fine tireads or rays of desi 'uated in Figure 2 by the reference numera 54, all of which emanate from the cuncentx ated light source 52 and projectx ri ry f the memb It w l e srved that these threads rays 5.4 of light are divided into radially projecting groups and that each of these groups consists of a Series of vertically diverging light rays. As appears most clearly in Figure2 the vertimovable rack member 32 is provided. with a longitudinally extending passage therethrqu ,h for the electric conductors 56 leading to the lamp socket 51.

mounted upon the vertically ertic-allyspaced relation with respect to said,

base plate. Suitable abutments 5.9 are provided upon the rods 12 to limit the upward movement of plate member ,57. In order to prevent tilting of the plate member 57 with respect to the horizontal this member is pro vided with a central elongated sleeve 60 which snugly embraces and is arranged to slide upon the upwardly extending sleeve 27 of the ba e plat 0- Mountfid upon the resiliently supported,

plate member 57 are a plurality of horizontally disposed centrally apertured plates 61 and 62, said plates being arranged for eccentric adjustment with respect to ea h other and to the supporting plate member 57 therefor. This adjustment. is effected by the means new to he described. As clearly appears in Figures 2 and 3 the plate 61, which is that disposed immediately above the plate 1nemher 57 is provided with a pair of diametri cally opposed radially projecting ears 63 and 64. The car 63 is apcrtured, as at .65, for insertion therethroug'h of a pivot pin 66 the lower end of which threadedly engages the plate member 51?. The opposed ear 64 of plate I 61 is provided with an upstanding lug 67 which is arranged for rotation about a vertical axis. Suitably journallcd upon the spring pressed plate member 57 in the immediate vicinity of. the lug 67 of plate 61 is a hori- Zontally arranged screw 68' having an operating handle .69 The screw 68 threadedly engages the lug 67 such that upon rotation thereof in one direction or another the plate 61 will be caused to move about the pivotpin 66, as a center. it will thus appear that upon manipulating the operating handle 69 of the screw the plate 61 may be caused to assume a position which is either concentric or eccentric with respect to the supporting plate member 57, as the case may he. During the shifting movement of plate 61. as effected by the screw 68, the central axis thereof will at all times traverse an are which intersects the vertical axis of the apparatus, the center of f this are being the pivot pin 66. Suitable pro ject-ions 70 and 71 respectively formed upon opposed faces of the stationary plate member 57 and the relatively movable plate 61 constitute bearing surfaces thercbetween and serve to maintain them in constant parallel relation.

The upper plate 62 is similarly mounted for relative movement in a horizontal plane with respect to the plate 61.

To this end 7 the plate 62 is also provided with a pair of diametrically opposed ears 72 and 73, said cars being respectively aperturcd to receive a pivot pin 74 and an upstanding lug 75. The pivot pin 74 is threadedly secured to the plate 61 at a point located between the opposed ears 63 and 64 thereof. The plate 61 is provided with an additional ear 76 upon which is suitably journalled a screw 77 for operatively engaging the upstanding lug of the upper plate 62. As in the case of screw 68, the screw 77 is also provided with an operating handle 78, the rotation of which will effect a horizontal shifting of plate 62 relative to plate 61. This relative movement of plate 62 with respect to plate 61 is of course independent of the similar movement between plate 61 and the spring pressed plate member 57, although it will be apparent that upon manipulating the screw 68 the plates 61 and 62 will be shifted in unison with respect to the plate member 57. During the shifting movement of plate 62, as effected by the screw 77, the central axis thereof will at all t mes traverse an are which intersects the vertical axis of the apparatus, the center of the are being, in this instance, the pivot pin 74. Suitable projections 79 and 80 respectively formed upon opposed faces of the relatively movable plates 61 and 62 constitute bearing surfaces therebetween for maintaining the same in constant parallel rela tion.

Secured upon the upper surface of the centrally apertured plate 62, preferably by the screws 81, is a reflector supporting ring 82, the upper edge of said ring being beveled, as at 83, to provide a seat for a reflector a. Preferably, a facing 84 of felt or similar cushioning material interposed between the seat 83 and the reflector positioned therein. It will be observed that the central apertures of plates 61 and 62 are of substantially the same diameter as the reflector supporting ring 82, this being in order to permit the base of the reflector to be forced downwardly against the female die 30. As clearly appears in Figures 2 and 7 to 10, inclusive, the base of the reflector a is provided with a central aperture 85 of a diameter greater than that of the male die -13, the latter being arranged for projection downwardly through said aperture 85.

Slidably mounted upon the rods 12 of the apparatus and arranged above the reflector a, is a horizontally disposed member 86 having a plurality of radially extending arms 87 and a central hub 88 arranged to slidably embrace the vertical rack member 32. The radial arms 87 of member 86 are each provided with an elongated slot 89, the several arms being so arranged that the slots 89 provided therein are respectively disposed in the circumferentially spaced vertical planes of the apertures 53 formed in the annular wall of the member 39. In other words, slot 89 is provided above each set of vertically spaced apertures 53. Super-imposed upon the top surface of the radially slotted memher 86 and secured thereto by means of the clips 90 is a ground plate 91.

As appears most clearly in Figure 2, the vertically slidable member 86 is provided with an annular depending flange 92 to the lower edge of which is secured a horizontally disposed flat ring 93, the securement being effected by means of the screws 94. The assembly, comprising the member 86, the quartz top plate 91 and the flat bottom ring 93, is so mounted upon the rods 12 and the rack member 32 that it will of its own weight move downwardly toward the reflector supporting ring 82. The reflector a is normally positioned between its supporting ring 82 and the bottom ring 93 of this vertically movable assembly. Assuming that a reflector a is positioned upon the cushioned seat 84 provided therefor in the ring 82, it will be obvious that when the flat ring 93 is lowered sufficiently to engage the upper or free edge of the reflector the latter will be caused to assume a position with the free edge thereof lymg m a horizontally disposed plane. In this connection it will be observed that the assembly, of which the flat ring 93 1s a part, is relatively movable wrta respectto the rack member 32, the flange 38 of the rack member bemg eugageable with the hub 88 of= the said assembly in order to raise the latter suf liciently to permit the poz-sitionment of the rc- Hector (1 therebencat-h. hen the rack lowered the assembly, due to the weight thereof, is also lowered until the bottom ring 93 engages the reflector a as shown in Figure 2. The central axis of the reflector will thus be assured of a vertical position and if the reflector is perfectly formed there should he a symmetrical distribution of reflected light about said central axis.

In order to determine the relative reflect-v ing efficiency of the reflector the rays or threads of light which emanate from the light source 52 arranged within the member 39 are employed in the manner now to be described. Assuming that the reflector a is theoretically correct in design and assuming further that itis properly centered in the apparatus, it will be apparent that the rays of light emanating from the light source 52 will impinge upon the concaved surface of the reflector and be reflected upwardly along the lines designated by reference numeral 94. An observer looking down upon the ground plate 91 will see that the reflected light rays 94 for each set of vertical- 1y spaced apertures 53 are symmetrically arranged with respect to the vertical axis of the apparatus. Furthermore, he will observe that all of the reflected rays pass through the radial slots 89, as is shown more or less diagrammatically in Figures 5, whereiOt 62 with respect to the plate 61.

in the reflected rays of light appear in the ground plate as points .95.

na' reflector which is theoretically corrct in' ,design the geometric axis thereof is and should be coincident with the optical axis thereof. It is the optical axis about which the reflected light rays should be unifgrmly distributed. In the great majority o cases,'however, the optical and geometrical axes of a'reflector are not one and the same and it is this condition which gives risot o faulty distribution of light from those reflectors wherein the lamp socket coincidence with its geometrical axis, the

problem is to determine the position of the optical axis without reference to the geometric axis ofthe reflector. In order to determine this the reflector a is positioned upon its cushioned seat 84 and the bottom ring 93 of the upper assembly is lowered until it engages with and causes the free edge of the reflector to assume a horizontal position. The rack member 32 together with its associated bulb 52 is then vertically adjusted so as to direct the reflected rays 94 toward the ground plate 91 in such mannet that the distance between the innermost and outermost rays of each group will not exceed the length of the slot 89 through which said group of reflected rays is adapted to pass. The adjusting screws 68 and77 are then manipuated to effect a relative shiftipg of the plate 61 with respect to its suppprting plate member 57 and of the plate By carefully adjusting one or both of the screws 68 and 77 the reflector a will be shifted latorally of the apparatus center line until a maximumnumber of the parallel reflected light rays 94 are projected through the radial slots 89 of member 86 to appear in the ground plate as points 95. Obviously, if, after careful adjustment of the screws 68 andW, only a few of these points 95 appear in the portions of the ground plate which cover the slots 89 while the majority appear to either side of these slots or do not appear at all, the reflector should be discarded because of its low reflecting efliciency. Figure 6 is adiagrammatic'sh'owing of the light rays as reflected from a relatively irie cientreiflector. Itis of course to be understood that a reflector is not to be discarded merely because all of the reflected light rays 94 do not pass through the slots 89, because, in the last analysis, it is the observenwho must determine whether a suflicient number of the reflected light rays 94 pass upwardly through theslots 89 to warrant the approval of'the' reflector. The severity of the test depeiids entirely upon the use for which the reflector is intended. For instance, automobile headlight reflectors would probably not be approved unless at least two or more of the reflected light rays 94- passed through each of the radial slots 89, while ordinary street lantern reflectors might well be approved it two or more of thereflected light rays passed through each of three of the slots 89 While only av single ray passed through the remaining slot.

Having once positioned the reflector a such that the maximum possible number of parallel reflected light rays pass through the radial slots 89 and having determined that its reflecting efliciency'i s high enough to warrant its'approval, the next step is to secure a suitable lamp socket supporting element uponth'e base of the reflector with the axis thereof coincident with the optical axis of the reflector. For the reflector a shown in Figure 2 the optical axis thereof is coincident" with the common vertical axis of the rack member 32' and the coacting dies 30 and 43. Obviously, the lamp socket supporting element should be coaxial with the redetern ined optical axis of the reflector. referably,"thisflsupporting element for the socket comprises a pair of cooperating flanged ferrules 95 and 96, the shanks of which are adapted-to be forced together with the flanges thereof embracing opposite surfaces'of the reflector. (See Figure 10.)

Figures 7 to 10, inclusive, illustrate the several steps employed in forcing the ferrules 95 and 96 together, the initial step being to position the ferrule 95 such that its shank projects loosely through the central aperture of the reflector atthe 'same time that the ferrule 96 is positioned upon the concaved upper edge 44 of the female die 30. The rack member 32 is then lowered, by means of the pinion gear engaging therewith, until the convex'ed bottom wall 4'2 of the male diemember 39 rests upon the flange of the ferrule 95 while the male die 43 is projected into the tubular shank thereof. (See Figures 2 and 8.) The reflector a having been shifted in ahorizontal plane by means of one or: both of the adjusting screws 68 and 77 to efl'ect the desired sition, the rack member 32 is depressed still further to force the tubular shank of ferrule 95 downwardly through the tubular shank of the bottom ferrule '96 thereby obtaining a foroe-fit between saidtubular shanks. In so depressing the rack member 32 beyond the position shown in Figure 2 the reflector (1, together with its supporting ring 82 and the superposed plates 57, 61 and 62, is forced downwardly against the compressive force exerted by the compression springs 58 with the result that the flanges of the ferrules 95 and 96 are respectively clamped securely against opposite sides of the reflector. \Vhen the ferrules have thus been clamped together and to the reflector, the rack member is raised, the compression springs 58 being then operative to lift the reflector upwardly and away from the lower die 30. The annular space 98 formed between the ferrule flanges and the edge of the aperture of the reflector may be filled with a suitable plastic material, such as cement (not shown), which is adapted to subsequently harden and so secure the parts permanently together. The ferrules, when clamped together as just described, provide a tubular sleeve constituting a support for the reflector lamp socket (not shown), the longitudinal axis of said sleeve and accordingly that of the lamp socket being coincident with the predeterminedly located optical axis of the reflector as distinguished from its geometrical axis. Inasmuch as the focal center of the reflector is at some point along the optical axis thereof it becomes a simple matter to so adjust the lamp socket axially with respect to its supporting sleeve that the reflector bulb is located at said focal center.

It will be understood, of course, that the invention as herein described and shown is susceptible of various changes and that such changes may be made from time to time without departing from the general spirit or principles of the invention. It is accordingly intended to claim the invention broadly, as well as specifically, as indicated by the appended claims.

What is claimed as new and useful is:

1. In a reflector optical analysis apparatus, in combination, a vertically movable lamp supporting member, a lamp supported upon the lower end of said member, an enclosure for said lamp, said enclosure being provided with a plurality of circumferentially spaced groups of vertically spaced apertures the axes of which converge at the center of said lamp, said lamp being so positioned with respect to a reflector to be analyzed that the rays of light emanating therefrom and projected through said apertures impinge upon said reflector, and means for positionally adjusting said reflector to obtain a maximum number of reflected light rays symmetrically arranged about the vertical axis of said lamp.

2. In a reflector testing apparatus, in combination, a light source, means for projecting a plurality of symmetrically arranged light rays upon the concaved surface of a reflector to be tested, translucent means disposed in a plane axially spaced from and paralleling that of the reflector rim for intercepting the light rays reflected from said reflector, and means for positionally adjusting said reflector laterally with respect to said light source until a maximum of the reflected light rays are brought into registry with said translucent means, the light source being then located along the optical axis of the reflector.

3. In a reflector testing apparatus, in combination, a light source, means for projecting upon a reflector to be tested a plurality of circumferentially spaced groups of diverging rays of light emanating from said light source, said groups of diverging light rays being arranged respectively in vertical planes intersecting in an axis common to said light source, means arranged in advance of said reflector and provided with a plurality of openings respectively disposed in said planes, and means for adjustably positioning said reflector with relation to said axis until a maximum number of the light rays of each group, as reflected by said reflector, are projected through its associated opening, the light source being then located along the focal axis of the reflector. E

4. In a reflector testing apparatus, in combination, a relatively fixed light source, means for projecting upon a reflector to be tested-a plurality of symmetrically arranged separated rays of light, means for positionally adjusting said reflector laterally with relation to the axis of said light rays, and means for visually determining when said axis is coinci dent with the focal axis of the reflector.

5. In a reflector testing apparatus, in combination, a relatively fixed light source, means for radially projecting upon a reflector to be tested a plurality of symmetrically arranged rays of light, means for disposing the geometric axis of said reflector in parallel relation with the central axis of said light rays, observation means respectively arranged for registry with the light rays reflected from said reflector, and means for positionally adjusting said reflector laterally with relation to said central axis such that when said reflected rays are in registry with said observation means said central axis is in coincidence with the focal axis of the reflector.

6. In a reflector testing apparatus, in combination, a light source, means for producing a series of circumferentially spaced groups of diverging light rays all of which emanate from said light source as a center, a member disposed in a plane normal to the central axis of said light rays and provided with radial q slots, each of said slots being disposed in a 1 plane common to the diverging rays of each group, and means for relatively adjusting a reflector to be tested and said light source. the reflecting efliciency of the reflector being determined by the number of the light rays of said groups which are projected, by said reflector, through the slots respectively associated therewith.

7. In an apparatus for locating the focal axis of a reflector, in combination, a light source. an enclosure therefor, said enclosure being apertured to produce a plurality of individualized light rays emanating from said light source as a center and incident upon a reflector to be tested, a plurality of translucent lenses respectively coordinated with said incident light rays for observing the reflections thereof as produced by said reflector, and means for positionally adjusting said reflector laterally with respect to said light source. the reflected light rays being uniformly projected upon said lenses when the light source is located along the true focal axis of the reflector.

8. In an apparatus for locating the focal axis of a reflector, in combination, a light source located along a predeterminedly fixed axis, means for shifting a reflector to be tested in a plane normal to said axis, means for projecting upon said reflector a series of individualized light rays emanating from said light source, and means for observing when the reflected light rays are symmetrically arranged about said predeterminedly fixed axis.

9. In an apparatus of the character described, in combination. an axially movable member constituting an enclosure for a light source, said enclosure being apertured to produce a plurality of individualized light rays emanating from said light source and incident upon a centrally apertured reflector, means for shifting said reflector in a plane normal to the axis of movement of said member, means for observing when said axis is coincident with the focal axis of the reflector, and means operatively associated with said axially movable member for securing a lamp socket support within the reflector aperture, the axis of said support being coincident with the focal axis of the reflector.

10. In an apparatus of the character described. in combination, means for supporting a reflector having a central aperture for loosely receiving a ferrule projected therethrough, a male member adapted to be axially projected into said ferrule, means for laterally shifting said reflector with respect to said ferrule, a light source carried by said male member, means for visually determining when the reflector is positioned such that the focal axis thereof extends through said light source, and means operatively associated with said male member for rigidly securing said ferrule upon said reflector when the latter is in the position so determined whereby to insure coincidence between the axis of the ferrule and the focal axis of the reflector.

11. In an apparatus of the character described, in combination, a base member, a reflector supporting member axially movable with respect to said base member, means for laterally shifting a reflector supported by said member with respect to the central axis of said base member, a light source located along said central axis and arranged to project a plurality of individualized light rays upon said reflector, means intercepting the light rays reflected by said reflector for determining when said central axis is in coincidence with the optical axis of the reflector, and means for securing a lamp socket supporting sleeve upon said reflector when said coincidence is effected, said last mentioned means being automatically operable to insure coincidence between the axis of said sleeve and the optical axis of said reflector.

In testimony whereof, I have hereunto affixed my signature.

HERBERT J. GRAHAM. 

